In situ irradiated XPS investigation on S-scheme TiO2/Bi2S3 photocatalyst with high interfacial charge separation for highly efficient photothermal catalytic CO2 reduction

•The TiO2/Bi2S3 S-scheme heterojunction is prepared by hydrothermal method.•The TiO2/Bi2S3 hybrid showed wide spectrum response and good photothermal effect.•An improved CO2 photoreduction performance was achieved by the hybrid.•DFT calculation and in-situ characterization were used to clarify the mechanism.